Copying or enlarging camera



J. BECKER, DECD.

E. BECKER, Aummsnuon.

COPYING 0R ENLARGING CAMERA.v

APPLICATION min OCT. 16. 1918.

1,342,735. Patented June 8, 1920.

G 2 SHEETS-SHEET I.

zrz l I MILL Inventor J. BECKER, DEC-D.

E. BECKER, ADMINISTRATOR.

COPHNG 0R ENLARGING CAMERA.

APPLICATION FILED OCT-16,1918.

Patented J une 8, 1920.

2 SHEETS-SHEET 2.

JOSEPH BECKER, OF WASHINGTON, DISTRICT OF COLUMBIA; EDMUND BECKERADMINISTRATOR OF SAID JOSEPH BECKER, DECEASED.

COPYING 0R. ENLARGING CAMERA.

Specification of Letters Patent.

Patented June 8, 1920.

Substitute for application Serial No. 727,548, filed. October 24, 1912.This application filed October 16,

To all whom it may concern:

Be it known that I, JosEPH BECKER, a citizen of the United States,residing at lVashington, in the District of Columbia, have invented anew and useful Improvement in Copying or Enlarging Cameras, of which thefollowing is a specification.

My present patent application, which 1s identified for convenience ofreference in my related applications or patents as Case Rd, is filed inplace of my herein merged and now abandoned prior application Case X,Serial No. 7275618, filed October 2 1, 1912.

My different related applications or patents, specifically referred toabove, or hereinafter, may all be listed in their letter name or filingdate order, as follows; Case K, filed July 10, 1905, now Patent1,103,342, issued July 141, 1914; Case 0, filed Feb. 9, 1910,

now Patent 1,103,343, issued July 1 1, 1914;

Case T, filed August 28, 1911, now Patent 1,1el-2,295, issued June 8,.1915; Case U, filed November 7, 191.1, now Patent 1,190,214, issuedJuly at, 1916; Case X (based on the present Figs. 1 to 5 but nowabandoned and merged in the present Case Bd) Serial No. 727,548, filedOctober 24, 1912; Case Y, Serial No. 732,488, filed November 20, 1912,now merged in and continued as Case Au; Case Au or continuation of Y,filed January 2-1, 1917, now Patent 1,280,688, issued October 8, 1918. a

My present invention consists mainly in a constant velocity ratiomechanism that is speeifii'zally adapted for use, as an auxiliaryinstrument in adjusting and regulating the automatic focusing mechanismdisclosed in my said Cases K, O. T, U, K, Y, and Au.

M 7 invention furthermore consists, incidently, in a novel modified formof the copying or enlarging camera seen in British Patent No. 12734 of1904 to Cook, which modification was specially devised by me to permitof using my reduction to zero principle in the adjustment and regulationoi the said Cook cameras for use with any one of different lenses.

1 shall first illustrate my invention as applied to cameras of my saidprior Cases K, C, T, and U, which are already provided with allnecessary adjusting means, but where the present constant velocity ratioSerial No. 258,467.

device may be used to insure that the focusing at a finite distanceshall be at a given predetermined scale.

Figure l is a plan view of a plantographic linkage of the kind speciallyadapted for use with the camera shown in Fig. 19 of my said Cases K andC.

Fig. 2 is another form of the same device with adjustments to permit ofsecuring other desirable velocity ratios.

Fig. 3 is a form specially adapted for use in my improved form of theCook camera.

Fig. 4 is a vertical longitudinal. section of my improved Cook camerafully adjusted and regulated for use, its frames and gear being shown inthe unity position.

Fig. 5 is a similar view of the same camera in one phase of the processof adjustment.

In. its preferred form, Fig. 1, the constant velocity ratio deviceconsists in an articulated parallelogram composed of bars 1, 2, 3, 41and pivoted as shown at points G, H, K and G, H, K. i The three parallelbars 2, 5 and 41 are provided withthree alined bores A, D,A of the exactsize required to respectively fit the pins A, D, A of'the camera seen inFig. 19 of my said prior Cases K and O.

lVhen this pantographic linkage is mounted on the camera it obliges pinsA and A to move simultaneously,not in the same direction as required infocusing gear, but in opposite directions; and not at a varying velocityratio as required in focusing gear, but at a constant velocity ratioequal to the ratio of GH to H'K or of (1- to 6. Moreover, the sameconstant proportion holds for the whole distances AD, DA so that we haveAD Ti In using this device in any camera some means must first beprovided to make due allowance for the extent, sign and location of theinternodal space NN of the lens. This is done in Fig. 19 of my saidCases K and C, by adjusting the longitudinal connections m and m whichinvolve the internodal distance, and this adjustment, is preferably madeautomatically without knowing the extent, sign or location of theinternodal distance by means of the infinity and Zero method ofadjustment disclosed in said Cases K and 0.

Assuming, therefore, that the pintles, A, A have been properly locatedon their respective frames by the infinity and zero method, thepantograph of the present Fig. 1 is mounted on the camera with bore A onpin A, bore D on pin D and bore A on pin A; and, when so mounted, itobliges the two end frames of the camera to move in opposite directionsfrom the zero position so that the Newtonian spaceelements PF, FP of thelens, henceforth respectively equal to the Newtonian space elements AD,DA of the gear, shall be in the constant ratio of a to b.

If now the camera frames be moved back and forth until the sharpestavailable image has been secured, we know that then by Newtons formula1F.F1=f 2 7 By equations 8 and 9 of my said prior Cases K and O, we alsohave W JT or, in view of equation 1 above In order to secure any desiredcopying factor n in the cameras of my Cases K, O, T and U, therefore,all that is necessary is to construct the linkage of Fig. 1 so as tosatisfy this last equation, equation 5.

If reduction be desired instead of enlarge ment, in the same ratio, allthat need be done is to turn the device through two right angles about Das axis to set bore A on pin A, and bore A on pin A.

In Fig. 2 I show a form capable of adjustment to permit of securing anyone of three different velocity ratios, to wit, 1 to 1; 9 to 1; and 1 to'1; corresponding, respectively, to copying factors of 1, 1.5, and 2. AtH the copying factor n is 1; at H it is 1.5; and at H it is 2. Thedrawing is to scale and the numbers 26, 4.0 and indicate relative sizesof the various dimensions.

In this form three separate bores D are needed, so that there shallalways be one in proper cooperative alinement with bores A and A.

The reason why the device as applied to my cameras must have a velocityratio equal. to the square of the desired copying factor is that it actson the Newtonian space elements of the focusing gear. In cases where itis used on space elements corresponding to the full conjugate focaldistances of the object and image from the nodal points, the velocityratio should be exactly equal to the copying factor.

This case presents itself in the camera shown, Figs. 7 and S of Britishpatent to Cook No. 12,734: of 1904:.

In Fig. 3 I show a form of my constant velocity ratio linkage that isspecially adapted for use in my improved form of Cook camera, the cameraand the linkage being both modified to act in combination while thecamera is being adjusted for use with any one of different lenses. Thisimproved Cook camera will hereinafter be referred to for convenience asthe Becker-Cook camera.

Becker-0007c camera, (Figs. 4L and 5).

My device is not only useful in Cook, but almost indispensable if thehighest attainable efficiency of the lens is to be secured, as willpresently appear.

The adjustment of the Cook camera in cases where the focal length of thelens is unknown is an uncertain tentative process made to depend uponthe securing of a sharp image of the same size as the original. (Seefirst six lines page 8 of the Cook specification.) Now, in order tosecure this equal size image, the operator must perform two mutuallyinterfering operations. In focusing he changes size; and in moving theframes to change size he spoils his focus. Moreover, even when Cook doessucceed in securing his desired final result, the same is generallyinaccurate because he works from the so-called optical center withoutmaking allowance for the internodal distance NN.

For present purposes the Cook camera should be made substantially as inFig. a, which shows the parts in what Cook would call the unityposition, because it is the position for copying factor 01 equal one.

Parts C, L and I, Fig. 4c, are, respectively, the object frame, lensframe, and image frame of the camera. The lens frame L is rigidlymounted on a bridge piece 7 which is removably fastened to the rails 10of the camera bed by screws 8. The upper inside edge of the rails, onlyone of which appears in the figure, is grooved at 11 to form a slidewayfor the carriages 12, 12. The upper face of carriage 12 is provided witha slideway .15 for a block 16 on which the object frame 0 is rigidlyfastened. In block 16 is threaded a clamp screw 17 for clamping theblock and its object frame 0 in any desired longitudinal adjustment oncarriage 12. The image frame I is similarly mounted in longitudinallyadjustable position on carriage 12 by block 16 sliding in groove 15 andheld by screw 1.7.

A central horizontal cross pin D connecting the guide rails 11 serves asa fulcrum for the quadrant 19 which radial cam slots 20, slidinglyengaged with pins A, A which are rigidly, but adj ustably connected withthe carriages 12, 12, respectively.

The adjustable connection of pin A with carriage 12 is established bymeans of an inclined bracket 1%, which is fastened to the under side ofcarriage 12 by screws 13, and which is provided with an inclinedadjustment or bracket slot 23 at any desired point of which the pin Amay be firmly clamped and held by nut or other suitable clamping means.The bracket 14 is divided by a narrow longitudinal vertical kerf intotwo similar bracket elements or walls adapted to admit and guide thequadrant 19 between them.

The adjustable connection of pin A with carriage 12 is similarlyestablished by an inclined adjustment or bracket slot 23 formed in thedivided bracket 14, which is fixed to its carriage12 by'screws 13 driveninto the bottom of carriage 12.

Bracket 14; has a hole V formed in alinement with the inclinedadjustment slot 23, and at the same level as pin D. The diameter ofthishole is made the same as that of pin D so that the hole may, asexplained later, be slid up to snugly admit pin D for holding thecarriage 12 in its zero positionj Bracket 1% has a similar hole Vi inalinement with adjustment slot 23, of the same diameter and at the samelevel as pin D to permit of holding carriage 12 in its zero position.

-The two adjustment or bracket slots 23, 23 are disposed in any desiredperpendicular relation as shown. The left end of quadrant 19 isperforated to admit a horizontal pin used for temporarily holding thequadrant with. its radial cam slots 20, 20 in anti-parallel relation tothe bracket slots 23, respectively, as shown in the unity position, Fig.l. The radial cam slot 20 and the bracket slot 23, being equally butoppositely inclined with reference to the horizontal line Vi W, are(according to the Merriam International VVebster of 1912) anti-parallel.Radial cam slot 20 and bracket slot 23 are anti-parallel for the samereason; and if the pintles A, A are supposed removed so as to permit offreely changing the distances lVD and D'VV, this anti-parallel relationof the grooves and slots persists as long as the quadrant 19 is held inits locked position by pin 30, vhich slides as a bolt throughn properlylocated opening 31, Fig. 5, in rail 10.

:xssuming that the exact position of the nodal points, N, N withrelation to the has perpendicular camera bed 10 has been predetermined,the lens frame L and the quadrant 19 are unmounted and. removed toprepare the camera for adjustment.

Carriage 12 is now slid up into its zero position, making lVD equal tozero, and it is. locked in such position by insertion of pin D; and thenhaving loosened clamp screw 17, the object frame O'is moved as requiredto bring its point P into coincidence with the known position of thenodal point N belonging to the object space; Finally screw 17 is firmlytightened to hold frame 0 in its thus determined proper adjustment oncarriage 12.

Pin D is withdrawn, and carriage 12 is slipped back to the left, and itwill be noted that henceforth the varying mechanical space element WDremains equal to the equally varying object distance PN.

Carriage 12"is now moved up into its zero position, making DlV equal tozero, and it is locked in such position by reinserting pin D; and then,having loosened the clamp screw 17, the image frame I is moved asrequired to bring its point P into coincidence with the known positionof the nodal point N belonging to the image space. Finally screw 17 isfirmly tightened to hold frame I in its thus determinedproper'adjustment on carriage 12.

Pin D is withdrawn anl carriage 12 is slipped back to the right, withits varying distance DVV constantly equal to the equally varyingdistance NP of the image receiving plane P.

The one-to-one pantograph of Fig. 3 is now mounted, as in Fig. 5, withbore A at bore D at D and bore A at W.

The lens frame L is then remounted and the frame I is moved into properposition to secure the sharpest image. As is surely kept equal to DlV bythe pantograph during this focusing operation, the image secured is theequal size image, and we have D equal to Dll equal to twice the focallength FN of the lens.

Temporary clamps, such as weights, are now applied to carriages 12, 12to hold the end frames 0 and I in their, thus determined unity positiongraphic linkage is removed. The quadrant 19 is now remounted and lockedin the unity or parallel position of Fig. 4 by means of slide bolt 30,and the pintles A, A are i.nserted and fixed at the points where thebracket slots 28,, 23 are crossed by the ra dial cam slots 20, 20. Asthese cam slots 20, 20 are in their anti-parallel relation to thebracket slots 23, 23, the pins A, A must now be situated exactly midwaybetween the vertical planes through W, D and V. If the five points W, A,D, A and N all be imagined as projected onto the lens axis and thepantothe unity position of Fig. 4:

In all other positions, and generally, we shall have wazaw f (6) alsoacldazf (7 where m] and do are the co-varying Newtonian space elementsof the focusing gear. Bolt 31 is now withdrawn to free the quadrant 19,and the device is ready for use.

In the structure illustrated I have adhered to Cooks idea of adjustingin the unity-position where the ratio IN/NP, or copying factor n, equalsone. This limitation, though convenient, is not essential.

To adjust and regulate my present BeckerCook camera at any preferredcopying factor 9L, use a pantograph ratio .ll-l/HK and a quadrant ratio(la/aw each equal to n.

Thus, to illustrate the application of the rule, suppose a is equal tounity, then the pantograph ratio Gl-l/I-IK should be 1, as in Fig. 1-.For a copying factor at equal 2, these same ratios'would be 2, and soon, bore :31 of F 5 being shifted to correspond.

No're 1.According to disclosures in my said Case Au my presentBecker-Cook camera has a basic angle delta (A) that is equal to oneright angle.

No'rn 2.In accordance with other disclosures of my said Case Au,however, the present Becker-Cook camera should. preferably be built witha basic angle delta (A) that is smaller than a right angle. Changing thebasic angle involves no change in principle.

Nora 3.The inclined bracket slots 23 and 23, in present Fig. 4:, shouldnot be confounded with inclined grooves 215 and 215 in Fig. 3 of my saidCase Au, where the present pintles A and A are identified as V and V; sothat the present Fig. 4, after completion of its adjustments, reallycorresponds to Fig. 1 of my said Case Au, and not to Fig. 3 of said CaseAu, as might easily and incorrectly be assumed.

No'rn 4.--The same said Case An, in connection. with its Fig. 7 and itsequation Ill. discloses how its special three-point method of adjustmentis applicable to the present form of Becker-Cook camera.

NOTE 5.Instead of plotting the unity positions of the end frames asexplained in my said Case Au, the same 3-point method may be used forlocating the above referred to N and N positions of the end frames, as,by plotting the distance to the right of Y, and the same distance to theleft of Y, marks Y and Y being those seen in Fig. 7 of my said Case Au.Moreover, in some forms of the device it would be easier to adjust andregulate the focusing mechanism proper by making 1) and DW each equal totwice 7 either with or without the pantograph of Fig. 3, before settingthe end frames. All such modifications in procedure may be made withoutproducing any change in the final result.

No'rn 6.-As it is easier to apply temporary clamps to carriages 12 and12 in the special form of structure that appears in Fig. at, than itwould be to apply such clamps to the end frames 0 and I of said Fig. 4as contemplated in my said Case Au, the three point process ofadjustment would be facilitated by first adjusting the focusingmechanism proper before paying any attention to the location of the endframes.

No'rn T. The present preferred form of my 3-point process of adjustmentmight then be described as comprising the following steps: (1) calculate7 by equation 11 of my said Case Au; (2) mark, on bed 10, the unityposition. U of frame 0, at distance 7 to the left of Y; (3) mark, on bed10, the unity position U of frame I, at distance 7 to the right of Y(41) utilizing the \Vl) equal zero position. set and temporarily clampcar riage 12 in position to make N D equal to twice 7; utilizing the DIVequal zero position set and temporarily clamp carriage 19. in theposition that makes DVV equal. to twice 7, (6) mount the sector 19 onits pivot D, and hold it in the anti-parallel position of Fig. 4: byinserting bolt 30; insert pintle A. at the crossing point of cam slot 20with bracket slot 23, and bolt it to the bracket 14!: in its thusdetermined proper position; (8) insert pintle A at the crossing point ofcam slot 20 with bracket slot 23 and bolt it firmly to bracket 14 in itsthus determined proper position; loosen screw 1.7 and bring frame 0 intoits unity position U, then clamp it firmly to its carriage 12 bytightening screw 17 (10) loosen screw 17 and bring frame I into itsunity position U, and then clamp it firmly to carriage 12 by tighteningscrew 17; (11) finally remove the temporary clamps ofcarriages 12, 12withdraw bolt 30, and the combination is ready for use.

No'rn 8.The zero position in my present F 4: making distances and, anddon equal zero, should not be confounded with the zero position of mysaid Case U making present distances (rd, and do equal to zero.

No'rn 9.By direct experiment with a very large lens of high grade, Ihave found that the calculated Gaussian focal length of equation eleven,in my said Case Au, may be used to plot, from Y and Y as origins, acomplete focusing scale that is not only accurate for determining focalposition, but also remarkably accurate for determining the scale ofreproduction or copying factor n.

N OTE 10.-Pintles A and A of the present Fig. l, correspond to pintles Aand A of my said Case U, and not to terminals A and A of my said CaseAu, where the present pintles A and A are identified as V and V.

N orn 11.In my said Case Au the present terminals W and W are found byplotting a distance AW or f, to the left of A; and by plotting an equaldistance AlV or f to the right of A.

NOTE l2.-The terminals A A of my said Case Au are found in the presentFig. 4 by plotting a distance WA or f, to the right of WV; and byplotting an equal distance VVA or f, to the left of N o'rn 13.-The CaseAn end frame terminals A, A may, therefore, be located on line WVV ofthe present Fig. 4: by simply producing the verticals aA and aA untilthey meet with the horizontal WW.

What I claim as my invention and desire to secure by Letters Patent is:

1. The combination with a photographic camera comprising a lens support,an image support and an object support, and ways adapted to guide two ofsaid supports with relation to the third; of mechanism for connectingthe said three supports to compel the image and object supports to movesimultaneously in opposite directions with relation to the lens supportat a constant velocity ratio.

2. The combination with a photographic camera comprising a lens support,an image relation to the third; of mechanism for con-.

necting the said three supports to compel the image and object supportsto move simultaneously in opposite directions with relation to the lenssupport at a constant velocity ratio, such mechanism consisting in alinkage pantograph. I

4. The combination with a copying or enlarging camera having focusinggear 'of the type adapted to determine structural co-varying spaceelements such as WVD and DW respectively equal to the full conjugatefocal distances PN, NP of the lens; such gear being so constructed as topermit of reducing either of its said mechanical space elements WVD andD W to zero value.

In testimony whereof, I have signed my name to this specification.

JOSEPH BECKER.

In the presence of- EDNA H. RAY.

